The production of exceedingly small sensing and control devices has been developed to a high state of perfection over the last 30 years. In the last 30 years, the manufacture of mass-produced microelectronic circuits on silicon wafers has become the forerunner of the production of various other devices by similar manufacturing techniques. The fabrication of novel three-dimensional microelectronic devices in a semiconductor crystal, typically silicon, has been accomplished by fabricating the device through many techniques including isotropic and anisotropic etching. These techniques utilize the crystalline structure of a single crystal semiconductor. The techniques had evolved to the point where devices that are only a few thousandths of an inch in dimension are manufactured in quantity.
The state of the art generally can be found in considering the cross-referenced pending patent applications, and in a number of published articles. The citation of this type of article in the present text is provided merely as background, and the articles are not deemed as prior art to the specific invention claimed in this application. Articles of particular interest are found in IEEE Transactions on Electronics Devices, Volume Ed-25, No. 10, October 1978, at pages 1178 and 1241. The article appearing at page 1178 is entitled "Fabrication of Novel Three-dimensional Microstructures by the Anisotropic Etching of (100) and (110) Silicon" by E. Bassous. The article appearing at page 1241 is entitled "Dynamic Micromechanics on Silicon: Techniques and Devices" by K. E. Petersen. Also of interest as general background is an article entitled "Silicon Micromechanical Devices" which was published on pages 44-55 of the April 1983 issue of Scientific American.
The articles and pending application referenced above show clearly that it is old, and the technique well-known, to manufacture micromechanical devices by etching into a single crystal silicon. The etching techniques generally rely on obtaining the maximum speed of etching, and as such, the planes within the crystal typically dictate the orientation of the device on the surface of the structure The dictation of the orientation of the manufactured device on the surface of a single crystal silicon provides a utilitarian way of producing certain individual devices. Typically, the silicon structure is separated after manufacture so that the individual devices can be utilized separately and the orientation of the device with respect to the crystalline structure usually leaves unused surfaces of the silicon crystal. Sometimes these unused surfaces are adapted for use as an area upon which integrated circuitry is placed to function with the device manufactured by the etching technique. In other cases, the area is merely wasted area.